3OSR

Maltose-bound maltose sensor engineered by insertion of circularly permuted green fluorescent protein into E. coli maltose binding protein at position 311

Summary for 3OSR

• Entry DOI: 10.2210/pdb3osr/pdb
• Related: 3OSQ
• Related PRD ID: PRD_900001
• Descriptor: Maltose-binding periplasmic protein,Green fluorescent protein, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: engineered protein, sensor protein, fluorescent protein, mbp, gfp, maltose sensor, transport protein
• Biological source: Escherichia coli O157:H7; More
• Cellular location: Periplasm : P0AEY0
• Total number of polymer chains: 2
• Total formula weight: 146068.22

Authors

Echevarria, I.M.,Marvin, J.S.,Looger, L.L.,Schreiter, E.R. (deposition date: 2010-09-09, release date: 2011-10-26, Last modification date: 2024-10-30)

Primary citation

Marvin, J.S.,Schreiter, E.R.,Echevarria, I.M.,Looger, L.L.
A genetically encoded, high-signal-to-noise maltose sensor.
Proteins, 79:3025-3036, 2011

PubMed Abstract: We describe the generation of a family of high-signal-to-noise single-wavelength genetically encoded indicators for maltose. This was achieved by insertion of circularly permuted fluorescent proteins into a bacterial periplasmic binding protein (PBP), Escherichia coli maltodextrin-binding protein, resulting in a four-color family of maltose indicators. The sensors were iteratively optimized to have sufficient brightness and maltose-dependent fluorescence increases for imaging, under both one- and two-photon illumination. We demonstrate that maltose affinity of the sensors can be tuned in a fashion largely independent of the fluorescent readout mechanism. Using literature mutations, the binding specificity could be altered to moderate sucrose preference, but with a significant loss of affinity. We use the soluble sensors in individual E. coli bacteria to observe rapid maltose transport across the plasma membrane, and membrane fusion versions of the sensors on mammalian cells to visualize the addition of maltose to extracellular media. The PBP superfamily includes scaffolds specific for a number of analytes whose visualization would be critical to the reverse engineering of complex systems such as neural networks, biosynthetic pathways, and signal transduction cascades. We expect the methodology outlined here to be useful in the development of indicators for many such analytes.

PubMed: 21989929
DOI: 10.1002/prot.23118

Experimental method

X-RAY DIFFRACTION (2 Å)